1. Field of the Invention
The present general inventive concept relates to a liquid crystal display (LCD), and more particularly, to an LCD device capable of performing column inversion or dot inversion, and a method of driving the same.
2. Description of the Related Art
Liquid crystal display (LCD) devices are compact and have a small power consumption compared to other types of display devices. The LCD devices are used in electronic devices, such as notebook computers and mobile phones. In particular, an active matrix type LCD device that uses a thin film transistor as a switching device, is especially appropriate for displaying moving pictures.
FIG. 1 is a circuit diagram of an LCD panel 10 of a conventional LCD device. Referring to FIG. 1, the LCD panel 10 includes a plurality of source lines S1 through S4, a plurality of gate lines G1 through G4, a plurality of switch transistors TFT, and a plurality of liquid crystal capacitors CLC.
Each pixel includes a switch transistor TFT and a liquid crystal capacitor CLC. The switch transistor TFT is turned on or off by a signal of one of the gate lines G1 through G4. A terminal of the switch transistor TFT is connected to one of the source lines S1 through S4. The liquid crystal capacitor CLC is connected between an other terminal (pixel electrode) of the switch transistor TFT and a common electrode. A common voltage VCOM, e.g. 0 volts, is applied to the common electrode.
In order to transmit image data to each pixel of the LCD panel 10, the gate lines G1 through G4 of the LCD panel 10 are sequentially activated. The image data applied to the source lines S1 through S4 is transmitted to the pixels connected to the activated gate lines G1 through G4.
Liquid crystal fills a space between the pixel electrode and the common electrode. When a voltage is applied to the pixel electrode and the common electrode, an electric field is formed in the liquid crystal. An intensity of the electric field is adjusted to control an amount of light passing through the liquid crystal, thereby displaying an image. If an electric field is continuously applied to the liquid crystal in only one direction, the liquid crystal may be degraded. To prevent this, an inversion method is used, in which a polarity of a source voltage (data voltage) with respect to the common voltage VCOM is inverted in order to drive the liquid crystal.
FIG. 2 illustrates conventional inversion methods. FIG. 2 illustrates a frame inversion method, a line inversion method, a column inversion method, and a dot inversion method. In FIG. 2, G1 through G4 correspond to the gate lines G1 through G4 of FIG. 1, and S1 through S4 correspond to the source lines S1 through S4 of FIG. 1. A pixel is located at an intersection of one gate line and one source line. FIG. 2 illustrates 16 screen images each composed of 4×4 pixels.
In the frame inversion method, the polarity of a pixel group consisting of sixteen pixels is inverted in each frame. In the line inversion method, the polarity of a pixel group consisting of four pixels is inverted in units of lines. In the column inversion method, the polarity of a pixel group consisting of four pixels is inverted in units of columns. In the dot inversion method, the polarity of a pixel group consisting of only one pixel is inverted in units of dots.
The frame inversion method requires a small amount of power but cannot display a high-definition screen image. The dot inversion method uses more power, but is capable of displaying a high-definition image by reducing flicker, and thus has been extensively applied to large-scale LCD devices.